#!usr/bin/env python3
from collections import defaultdict,deque
from heapq import heappush, heappop
from itertools import permutations
import sys
import math
import bisect
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def I(): return int(sys.stdin.readline())
def LS():return [list(x) for x in sys.stdin.readline().split()]
def S():
    res = list(sys.stdin.readline())
    if res[-1] == "\n":
        return res[:-1]
    return res
def IR(n):
    return [I() for i in range(n)]
def LIR(n):
    return [LI() for i in range(n)]
def SR(n):
    return [S() for i in range(n)]
def LSR(n):
    return [LS() for i in range(n)]

sys.setrecursionlimit(1000000)
mod = 1000000007

def solve():
    n,m = LI()
    c = LI()
    dp = [float("inf")]*(n+1)
    dp[0] = 0
    for i in range(m):
        ci = c[i]
        for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
    print(dp[n])
    return

#Solve
if __name__ == "__main__":
    solve()
 from collections import defaultdict,deque from heapq import heappush, heappop from itertools import permutations import sys sys import math math import bisect bisect int(x) for x in sys.stdin.readline().split() for x in sys.stdin.readline().split() x sys.stdin.readline().split() sys.stdin.readline().split sys.stdin.readline() sys.stdin.readline sys.stdin sys stdin readline split for x in sys.stdin.readline().split() int(x) int x def LI(): return [int(x) for x in sys.stdin.readline().split()] LI def I(): return int(sys.stdin.readline()) I list(x) for x in sys.stdin.readline().split() for x in sys.stdin.readline().split() x sys.stdin.readline().split() sys.stdin.readline().split sys.stdin.readline() sys.stdin.readline sys.stdin sys stdin readline split for x in sys.stdin.readline().split() list(x) list x def LS():return [list(x) for x in sys.stdin.readline().split()] LS def S():
    res = list(sys.stdin.readline())
    if res[-1] == "\n":
        return res[:-1]
    return res S res = list(sys.stdin.readline()) res list(sys.stdin.readline()) list sys.stdin.readline() sys.stdin.readline sys.stdin sys stdin readline if res[-1] == "\n":
        return res[:-1]
     res[-1] == "\n" res[-1] res -1 "\n" return res[:-1] res[:-1] res :-1 -1 return res res def IR(n):
    return [I() for i in range(n)] IR I() for i in range(n) for i in range(n) i range(n) range n for i in range(n) I() I return [I() for i in range(n)] [I() for i in range(n)] n n def LIR(n):
    return [LI() for i in range(n)] LIR LI() for i in range(n) for i in range(n) i range(n) range n for i in range(n) LI() LI return [LI() for i in range(n)] [LI() for i in range(n)] n n def SR(n):
    return [S() for i in range(n)] SR S() for i in range(n) for i in range(n) i range(n) range n for i in range(n) S() S return [S() for i in range(n)] [S() for i in range(n)] n n def LSR(n):
    return [LS() for i in range(n)] LSR LS() for i in range(n) for i in range(n) i range(n) range n for i in range(n) LS() LS return [LS() for i in range(n)] [LS() for i in range(n)] n n sys.setrecursionlimit(1000000) sys.setrecursionlimit sys setrecursionlimit 1000000 mod = 1000000007 mod 1000000007 def solve():
    n,m = LI()
    c = LI()
    dp = [float("inf")]*(n+1)
    dp[0] = 0
    for i in range(m):
        ci = c[i]
        for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
    print(dp[n])
    return

#Solve solve n,m = LI() n LI() LI m c = LI() c LI() LI dp = [float("inf")]*(n+1) dp [float("inf")]*(n+1) [float("inf")] float("inf") float "inf" n+1 n 1 dp[0] = 0 dp[0] dp 0 0 for i in range(m):
        ci = c[i]
        for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
     i range(m) range m ci = c[i] ci c[i] c i for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
     j range(n) range n nj = j+ci nj j+ci j ci if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
     nj <= n nj n nd = dp[j]+1 nd dp[j]+1 dp[j] dp j 1 if nd < dp[nj]:
                    dp[nj] = nd
     nd < dp[nj] nd dp[nj] dp nj dp[nj] = nd dp[nj] dp nj nd print(dp[n]) print dp[n] dp n return if __name__ == "__main__":
    solve() __name__ == "__main__" __name__ "__main__" solve() solve def I(): return int(sys.stdin.readline()) def I(): return int(sys.stdin.readline()) I def solve():
    n,m = LI()
    c = LI()
    dp = [float("inf")]*(n+1)
    dp[0] = 0
    for i in range(m):
        ci = c[i]
        for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
    print(dp[n])
    return

#Solve def solve():
    n,m = LI()
    c = LI()
    dp = [float("inf")]*(n+1)
    dp[0] = 0
    for i in range(m):
        ci = c[i]
        for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
    print(dp[n])
    return

#Solve solve mod = 1000000007 1000000007 mod def S():
    res = list(sys.stdin.readline())
    if res[-1] == "\n":
        return res[:-1]
    return res def S():
    res = list(sys.stdin.readline())
    if res[-1] == "\n":
        return res[:-1]
    return res S def LI(): return [int(x) for x in sys.stdin.readline().split()] def LI(): return [int(x) for x in sys.stdin.readline().split()] LI def LSR(n):
    return [LS() for i in range(n)] def LSR(n):
    return [LS() for i in range(n)] LSR def LS():return [list(x) for x in sys.stdin.readline().split()] def LS():return [list(x) for x in sys.stdin.readline().split()] LS def IR(n):
    return [I() for i in range(n)] def IR(n):
    return [I() for i in range(n)] IR def SR(n):
    return [S() for i in range(n)] def SR(n):
    return [S() for i in range(n)] SR def LIR(n):
    return [LI() for i in range(n)] def LIR(n):
    return [LI() for i in range(n)] LIR
#!usr/bin/env python3
from collections import defaultdict,deque
from heapq import heappush, heappop
from itertools import permutations
import sys
import math
import bisect
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def I(): return int(sys.stdin.readline())
def LS():return [list(x) for x in sys.stdin.readline().split()]
def S():
    res = list(sys.stdin.readline())
    if res[-1] == "\n":
        return res[:-1]
    return res
def IR(n):
    return [I() for i in range(n)]
def LIR(n):
    return [LI() for i in range(n)]
def SR(n):
    return [S() for i in range(n)]
def LSR(n):
    return [LS() for i in range(n)]

sys.setrecursionlimit(1000000)
mod = 1000000007

def solve():
    n,m = LI()
    c = LI()
    dp = [float("inf")]*(n+1)
    dp[0] = 0
    for i in range(m):
        ci = c[i]
        for j in range(n):
            nj = j+ci
            if nj <= n:
                nd = dp[j]+1
                if nd < dp[nj]:
                    dp[nj] = nd
    print(dp[n])
    return

#Solve
if __name__ == "__main__":
    solve()

